Authors and publishers of books, and other such media, often publish or provide new versions or editions of their books. When a potential customer is attempting to purchase one of these books, the customer might have the option of purchasing the current edition or a prior edition. The cost difference between the current edition and the prior edition may be significant, such that for customers such as students with limited funds, a customer may prefer to purchase an earlier edition if the differences between the editions are relatively minor. It will often be difficult for the customer to determine the type and extent of the differences between the books, particularly if the books are electronic books, or “e-books,” offered from a provider such that the customer cannot first obtain and compare the books. Customers can thus end up spending more money than desired to ensure that they have adequate content from the current version, or may end up disappointed with an earlier version when the extent of the changes is significant.